This post is a golden trove of all the links that you'll ever need if you're looking to start your musical career, a lot of it though will take a considerable amount of time to learn though if you're trying to make it big. Also, considering that this post is relatively old now, a lot of new tools have sprung up and some of the old ones are no longer viable.
For the productivity tools, Trello is very much still relevant but newer ones like Notion, Process.st and Asana have been taking the internet by storm with better features suited for breaking down the production process into smaller, much more manageable chunks. From the contract creation period, lyric writing process, tool check listing, royalty programs, and etc–you can literally outline it now.
For the video tools, a cracked version of Adobe, Final Cut Pro, and the like are still amazing investments if you're aiming for high-quality music videos. I know these don't come cheap, but it all adds to the value that you can produce.
Lastly, for the website tools are all still very applicable today, this is a really important aspect of being a producer nowadays–building your brand through a domain or website. I'd argue that it is close and as important as your physical studio now. But aside from utilizing tools that are available to us, getting the help of professionals, say, hiring remote web developers, could be a vital tool in securing a solid website built from scratch. They don't have to be a 100% expensive either, you can follow guides like this one on how to find a webdev that can help you that's still within your budget.